263 строки
6.4 KiB
C
263 строки
6.4 KiB
C
/*
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* include/asm-xtensa/checksum.h
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_CHECKSUM_H
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#define _XTENSA_CHECKSUM_H
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#include <linux/in6.h>
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#include <xtensa/config/core.h>
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/*
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* computes the checksum of a memory block at buff, length len,
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* and adds in "sum" (32-bit)
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*
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* returns a 32-bit number suitable for feeding into itself
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* or csum_tcpudp_magic
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*
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* this function must be called with even lengths, except
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* for the last fragment, which may be odd
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*
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* it's best to have buff aligned on a 32-bit boundary
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*/
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asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
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/*
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* the same as csum_partial, but copies from src while it
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* checksums, and handles user-space pointer exceptions correctly, when needed.
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*
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* here even more important to align src and dst on a 32-bit (or even
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* better 64-bit) boundary
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*/
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asmlinkage unsigned int csum_partial_copy_generic( const char *src, char *dst, int len, int sum,
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int *src_err_ptr, int *dst_err_ptr);
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/*
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* Note: when you get a NULL pointer exception here this means someone
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* passed in an incorrect kernel address to one of these functions.
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*
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* If you use these functions directly please don't forget the access_ok().
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*/
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static inline
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unsigned int csum_partial_copy_nocheck ( const char *src, char *dst,
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int len, int sum)
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{
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return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
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}
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static inline
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unsigned int csum_partial_copy_from_user ( const char *src, char *dst,
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int len, int sum, int *err_ptr)
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{
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return csum_partial_copy_generic ( src, dst, len, sum, err_ptr, NULL);
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}
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/*
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* These are the old (and unsafe) way of doing checksums, a warning message will be
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* printed if they are used and an exeption occurs.
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*
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* these functions should go away after some time.
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*/
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#define csum_partial_copy_fromuser csum_partial_copy
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unsigned int csum_partial_copy( const char *src, char *dst, int len, int sum);
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/*
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* Fold a partial checksum
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*/
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static __inline__ unsigned int csum_fold(unsigned int sum)
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{
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unsigned int __dummy;
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__asm__("extui %1, %0, 16, 16\n\t"
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"extui %0 ,%0, 0, 16\n\t"
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"add %0, %0, %1\n\t"
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"slli %1, %0, 16\n\t"
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"add %0, %0, %1\n\t"
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"extui %0, %0, 16, 16\n\t"
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"neg %0, %0\n\t"
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"addi %0, %0, -1\n\t"
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"extui %0, %0, 0, 16\n\t"
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: "=r" (sum), "=&r" (__dummy)
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: "0" (sum));
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return sum;
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}
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/*
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* This is a version of ip_compute_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*/
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static __inline__ unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl)
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{
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unsigned int sum, tmp, endaddr;
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__asm__ __volatile__(
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"sub %0, %0, %0\n\t"
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#if XCHAL_HAVE_LOOPS
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"loopgtz %2, 2f\n\t"
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#else
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"beqz %2, 2f\n\t"
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"slli %4, %2, 2\n\t"
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"add %4, %4, %1\n\t"
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"0:\t"
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#endif
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"l32i %3, %1, 0\n\t"
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"add %0, %0, %3\n\t"
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"bgeu %0, %3, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"addi %1, %1, 4\n\t"
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#if !XCHAL_HAVE_LOOPS
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"blt %1, %4, 0b\n\t"
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#endif
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"2:\t"
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/* Since the input registers which are loaded with iph and ihl
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are modified, we must also specify them as outputs, or gcc
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will assume they contain their original values. */
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: "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr)
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: "1" (iph), "2" (ihl));
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return csum_fold(sum);
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}
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static __inline__ unsigned long csum_tcpudp_nofold(unsigned long saddr,
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unsigned long daddr,
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unsigned short len,
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unsigned short proto,
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unsigned int sum)
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{
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#ifdef __XTENSA_EL__
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unsigned long len_proto = (ntohs(len)<<16)+proto*256;
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#elif defined(__XTENSA_EB__)
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unsigned long len_proto = (proto<<16)+len;
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#else
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# error processor byte order undefined!
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#endif
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__asm__("add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"add %0, %0, %2\n\t"
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"bgeu %0, %2, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"add %0, %0, %3\n\t"
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"bgeu %0, %3, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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: "=r" (sum), "=r" (len_proto)
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: "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum));
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return sum;
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}
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/*
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* computes the checksum of the TCP/UDP pseudo-header
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* returns a 16-bit checksum, already complemented
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*/
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static __inline__ unsigned short int csum_tcpudp_magic(unsigned long saddr,
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unsigned long daddr,
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unsigned short len,
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unsigned short proto,
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unsigned int sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
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}
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/*
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* this routine is used for miscellaneous IP-like checksums, mainly
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* in icmp.c
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*/
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static __inline__ unsigned short ip_compute_csum(unsigned char * buff, int len)
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{
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return csum_fold (csum_partial(buff, len, 0));
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}
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#define _HAVE_ARCH_IPV6_CSUM
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static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
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struct in6_addr *daddr,
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__u32 len,
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unsigned short proto,
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unsigned int sum)
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{
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unsigned int __dummy;
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__asm__("l32i %1, %2, 0\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %2, 4\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %2, 8\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %2, 12\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %3, 0\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %3, 4\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %3, 8\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"l32i %1, %3, 12\n\t"
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"add %0, %0, %1\n\t"
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"bgeu %0, %1, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"add %0, %0, %4\n\t"
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"bgeu %0, %4, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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"add %0, %0, %5\n\t"
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"bgeu %0, %5, 1f\n\t"
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"addi %0, %0, 1\n\t"
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"1:\t"
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: "=r" (sum), "=&r" (__dummy)
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: "r" (saddr), "r" (daddr),
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"r" (htonl(len)), "r" (htonl(proto)), "0" (sum));
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return csum_fold(sum);
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}
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/*
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* Copy and checksum to user
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*/
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#define HAVE_CSUM_COPY_USER
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static __inline__ unsigned int csum_and_copy_to_user (const char *src, char *dst,
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int len, int sum, int *err_ptr)
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{
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if (access_ok(VERIFY_WRITE, dst, len))
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return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr);
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if (len)
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*err_ptr = -EFAULT;
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return -1; /* invalid checksum */
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}
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#endif
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